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4 Factors That Must Be Addressed During Product Lifecycle Simulation

Product lifecycle simulation is an effective tool for determining how long electronics in automotive and other applications will perform before failing. However, there are four distinct categories of electronics with disparate levels of lifetime expectations:

Low-end consumer products also have low-end longevity expectations. In fact, these electronics – toys, pedometers, gadgets, etc. – are not viewed as reliable for any extended period of time, and their planned obsolescence is expected by consumers.

Mainstream consumer electronics like cell phones and desktop/laptop computers generally have lifetimes spanning 18-36 months. Large home appliances are anticipated to be reliable anywhere from 7 to 15 years.

Commercial electronics are generally superior to their consumer counterparts and, as a result, are held to higher reliability standards. Examples such as internal/external medical devices, high-end servers and industrial controls are estimated to perform anywhere from 5-15 years.

Highly regulated electronics, as the category name implies, are among the most expensive and standardized products available, and usually have some type of warranty attached. Automotive, civil/military avionic and telecommunications products are expected to be reliable for no less than a decade and, in the case of avionics and telecommunications equipment, up to 30 years. Solar components and equipment are increasingly becoming standardized and, with that, comes reliability and warranty expectations of approximately 25 years.

Meeting these expectations requires that reliability engineers create simulations that confirm or evaluate the lifecycle – and that’s a tall order regardless of electronics type. Why? Life cycles can be complex. Use environments vary and, therefore, assumptions are made about certain things like components conforming to datasheet values; the quality of the manufactured assembly; and, that component behaviors will be exactly as anticipated.

These are reasonable assumptions for simulation but there are specific factors that, if overlooked in deference to assumptions, are cause for concern and could be costly in time, money and reliability:

Thermal stresses in the environment, particularly ambient temperatures, present complexities that cannot be accurately represented within one 24-hour period. Flight profiles, high load periods, heat exuded by surrounding equipment and other outside influences introduced by end users or OEMs must be factored into the equation and mitigated within the design.

Thermal stresses in the product are identified and understood by the specific power dissipating components. Isolating these components is most accurately accomplished through power dissipation analysis at the design phase, using thermal simulation tools like FloTherm to evaluate the temperatures the device will reach within its enclosure.

Mechanical stresses in the environment are caused by shock and vibration events. In automotive applications, these events are largely random and can be initiated by any number of occurrences – potholes, door closure, road vibration, rotating machinery, etc. Estimating the frequency of shock and vibration and understanding the vibration environment not only helps identify failure mechanisms, it allows for accurate prediction of probability to failure.

The duty cycle has an obvious impact on reliability, as the more a component is used, the sooner it will wear out. Capturing an accurate measurement of the proportionate time of operation to predict reliability requires specific knowledge and simulation of time in use, cycles per day, flights per year, dormant conditions, intensity of use, low to high power cycles and low data rates vs. maximum loads.